TAP OR FILTERED? Distilled or mineralised? Ionised or reverse osmosis? The offerings in the department stores are so varied it has prompted the Consumer Council to regularly test water-processing devices. Last year's test indicated that the eight models of countertop water filters tested were able to effectively remove contaminants as claimed. A few could also remove dissolved metals.
For removing dissolved metals or fluoride, the report says water filters with ion exchange resin are preferred.
Tests by the council in 1997 on water ionisers, water magnetisers or activator water units yielded less satisfactory performances. For those claiming to produce alkaline water rich in minerals such as calcium, the alkalinity and calcium levels in the test did not rise to the values claimed by the manufacturers.
Hildemar Dos Santos, director of Hong Kong Adventist Hospital's Lifestyle Management Centre, says ionised water is 'a big joke' because there is no proof that ionised water can produce a change in the pH of blood. 'If you want to alkalise your body, you have to add recarbonater or take calcium pills. If you take alkaline food your stomach becomes alkaline and will affect the function of its hydrochloric acid,' Dr Santos said.